JP7334047B2 - Image display device and circularly polarizing plate used in the image display device - Google Patents

Description

The present invention relates to an image display device and a circularly polarizing plate used in the image display device.

Image display devices typified by liquid crystal display devices and electroluminescence (EL) display devices (eg, organic EL display devices and inorganic EL display devices) are rapidly spreading. Furthermore, in recent years, the development of bendable or foldable image display devices is underway. However, in a bendable or foldable image display device, there is a problem that when an image is viewed in a bent state, a difference in color occurs between the images on both sides of the bent portion.

JP 2017-203987 A

The present invention has been made to solve the above-mentioned conventional problems, and its main purpose is to display an image in which the difference in specular hue between the images on both sides of the folded portion is small when the image is viewed in the folded state. It is to provide a device.

The image display device of the present invention comprises: a first image display portion; a second image display portion; The first image display portion and the second image display portion are configured to be foldable at the fold center. The first image display unit has, in order from the viewing side, a first polarizer, a first retardation layer having a circularly polarized light function or an elliptically polarized light function, and a first display cell; The image display section has, in order from the viewing side, a second polarizer, a second retardation layer having a circularly polarized light function or an elliptically polarized light function, and a second display cell. The first polarizer and the second polarizer are arranged such that their absorption axes are in a line-symmetrical relationship with respect to the bending center; and the first retardation layer and the second retardation layer , are arranged such that their respective slow axes are line-symmetrical with respect to the bending center.
In one embodiment, the image display device has specular reflection hues (a ^* ₁ , b ^* ₁ ) in a 30° polar angle direction of the first image display unit and 30° polar angle of the second image display unit. directional specular hue (a ^* ₂ , b ^* ₂ ) satisfies the following relationship:
|a ^* ₁ -a ^* ₂ |<1.00
|b ^* ₁ −b ^* ₂ |<1.00
In one embodiment, the first retardation layer and the second retardation layer are each a single layer, Re (550) of each retardation layer is 100 nm to 180 nm, and the first retardation layer The angle between the slow axis of and the absorption axis of the first polarizer is 40 ° to 50 °, and the slow axis of the second retardation layer and the absorption axis of the second polarizer. The angle is 40°-50°. In this case, typically, the first image display section further has a retardation layer exhibiting refractive index characteristics of nz>nx=ny between the first retardation layer and the first display cell. , the second image display section further includes a retardation layer exhibiting a refractive index characteristic of nz>nx=ny between the second retardation layer and the second display cell.
In one embodiment, each of the first retardation layer and the second retardation layer has a laminated structure of an H layer and a Q layer, and Re (550) of each H layer is 200 nm to 300 nm. and the Re(550) of each Q layer is 100 nm to 180 nm; the angle formed by the slow axis of the H layer of the first retardation layer and the absorption axis of the first polarizer is 10° to 20° and the angle formed by the slow axis of the Q layer of the first retardation layer and the absorption axis of the first polarizer is 70 ° to 80 °; the slow phase of the H layer of the second retardation layer The angle formed between the axis and the absorption axis of the second polarizer is 10° to 20°, and the angle formed between the slow axis of the Q layer of the second retardation layer and the absorption axis of the second polarizer is 70° to 80°.
In one embodiment, the first image display section and the second image display section are integrated, and a bending center is defined as a boundary between the first image display section and the second image display section. .
In one embodiment, the image display device is an organic electroluminescence display device.
According to another aspect of the present invention, there is provided a circularly polarizing plate for use in the above image display device. The circularly polarizing plate has a first portion corresponding to the first image display portion and a second portion corresponding to the second image display portion integrated, and a boundary between the first portion and the second portion The bending center is defined as The first part has a first polarizer and a first retardation layer with circular polarization function or elliptical polarization function; the second part has a second polarizer and circular polarization function or elliptical polarization function a second retardation layer; the first polarizer and the second polarizer are arranged so that their absorption axes are in a line-symmetrical relationship with respect to the bending center; The retardation layer and the second retardation layer are arranged such that their respective slow axes are line-symmetrical with respect to the bending center.
In one embodiment, each of the first retardation layer and the second retardation layer is an alignment fixed layer of a liquid crystal compound.
In one embodiment, each of the first polarizer and the second polarizer is an alignment fixed layer of a liquid crystal compound.

According to the present invention, in the bendable or foldable image display device, the absorption axis of the polarizer and the slow axis of the retardation layer in the image display portions on both sides of the bent portion are line-symmetrical with respect to the bent portion. By setting the positional relationship, it is possible to obtain an image display device in which, when the image is viewed in the folded state, the difference in specular reflection hue between the images on both sides of the folded portion is small.

1 is a schematic plan view of an image display device according to an embodiment of the present invention, viewed from the viewing side; FIG. FIG. 2(a) is a schematic cross-sectional view of the image display device of FIG. 1 taken along line II-II; FIG. 2(b) is a schematic cross-sectional view showing a state in which the image display device of FIG. 2(a) is folded. is. FIG. 10 is a schematic cross-sectional view showing a folded state of the image display device according to another embodiment of the present invention; 4A to 4C are schematic plan views showing modifications of the relationship between the absorption axis direction of the polarizer and the slow axis direction of the retardation layer in the image display device of FIGS. 1 and 2, respectively. is. 4 is a schematic cross-sectional view of an image display device according to another embodiment of the invention; FIG. 4 is a photographic image showing a comparison of the state of reflected hues of the left screen and the right screen of the organic EL display device of Example 1 with the state of the reflected hues of the left screen and the right screen of the organic EL display device of Comparative Example 1. FIG.

Embodiments of the present invention will be described below, but the present invention is not limited to these embodiments.

(Definition of terms and symbols)
Definitions of terms and symbols used herein are as follows.
(1) refractive index (nx, ny, nz)
"nx" is the refractive index in the direction in which the in-plane refractive index is maximum (i.e., slow axis direction), and "ny" is the in-plane direction orthogonal to the slow axis (i.e., fast axis direction) and "nz" is the refractive index in the thickness direction.
(2) In-plane retardation (Re)
“Re(λ)” is an in-plane retardation measured at 23° C. with light having a wavelength of λ nm. For example, "Re(550)" is the in-plane retardation measured with light having a wavelength of 550 nm at 23°C. Re(λ) is obtained by the formula: Re(λ)=(nx−ny)×d, where d (nm) is the thickness of the layer (film).
(3) Thickness direction retardation (Rth)
“Rth(λ)” is the retardation in the thickness direction measured at 23° C. with light having a wavelength of λ nm. For example, “Rth(550)” is the retardation in the thickness direction measured at 23° C. with light having a wavelength of 550 nm. Rth(λ) is determined by the formula: Rth(λ)=(nx−nz)×d, where d (nm) is the thickness of the layer (film).
(4) Nz Coefficient The Nz coefficient is obtained by Nz=Rth/Re.
(5) Angles References to angles in this specification include clockwise and counterclockwise rotations with respect to a reference direction unless otherwise specified. For example, simply describing "45°" means 45° or -45°.

A. Overall Configuration of Image Display Device FIG. 1 is a schematic plan view of an image display device according to an embodiment of the present invention as seen from the viewing side; FIG. Fig. 2(b) is a schematic cross-sectional view showing a state in which the image display device of Fig. 2(a) is folded; Fig. 3 is an image display according to another embodiment of the present invention; It is a schematic sectional drawing which shows the state which bent the apparatus. The image display device 100 includes a first image display section 10, a second image display section 20, and a bend defined as a straight line connecting a side of the first image display section 10 and a side of the second image display section 20. a center C; In the image display device 100, the first image display section 10 and the second image display section 20 are configured to be foldable at the folding center C, and in one embodiment, foldable. The first image display section 10 has a first polarizer 12, a first retardation layer 14 having a circularly polarized light function or an elliptically polarized light function, and a first display cell 16 in this order from the viewing side. The second image display section 20 has a second polarizer 22, a second retardation layer 24 having a circularly polarized light function or an elliptical polarized light function, and a second display cell 26 in this order from the viewing side. In the embodiment of the present invention, the first polarizer 12 and the second polarizer 22 are arranged such that the absorption axis _A1 of the first polarizer 12 and the absorption axis _A2 of the second polarizer 22 are aligned with respect to the bending center C. They are arranged so as to have a line-symmetrical relationship (that is, so as to overlap when folded at the folding center C). Further, in the first retardation layer 14 and the second retardation layer 24, the slow axis S1 of the first retardation layer ₁₄ and the slow axis _S2 of the second retardation layer 24 are aligned with respect to the bending center C. They are arranged so as to have a line-symmetrical relationship. With such a configuration, it is possible to obtain an image display device in which, when the image is viewed in the folded state, the difference in specular reflection hue between the images on both sides of the folded portion is small. The image display device may be configured such that the first image display section 10 and the second image display section 20 connected as shown in FIG. The first image display section 10 and the second image display section 20 may be configured to be foldable. In the embodiment of FIG. 3 , the folding center C is defined as the boundary between the first image display portion 10 and the second image display portion 20 .

In the embodiment of the present invention, as described above, the absorption axis _A1 of the first polarizer 12, the absorption axis _A2 of the second polarizer 22, the slow axis S1 of the first retardation layer ₁₄ , and the second It is sufficient that the slow axis _S2 of the retardation layer 24 has a line-symmetric relationship with respect to the bending center C, respectively. Therefore, the axial relationship between the absorption axes A ₁ and A ₂ and the slow axes S ₁ and S ₂ is not limited to the configuration shown in FIG. 1, and any appropriate axisymmetric relationship can be adopted. A representative example of the line-symmetrical relationship is the configuration shown in FIGS. 4(a) to 4(c). The line-symmetrical relationship is preferably the configuration shown in FIG. With such a configuration, the manufacturing efficiency of the image display device is excellent, and the axial relationship can be easily adjusted. Furthermore, with such a configuration, it may be possible to bond the single film to the first image display portion and the second image display portion in one operation.

In one embodiment, the image display device 100 has specular reflection hues (a ^* ₁ , b ^* ₁ ) in the direction of the 30° polar angle of the first image display unit 10 and the 30° polar angle of the second image display unit 20. The direction specular hue (a ^* ₂ , b ^* ₂ ) satisfies the following relationship. In this case, the azimuth angle can be, for example, 110°-130° for the left screen and 50°-70° for the right screen.
|a ^* ₁ -a ^* ₂ |<1.00
|b ^* ₁ −b ^* ₂ |<1.00
That is, according to the embodiment of the present invention, by adopting the configuration as described above, when the image is viewed in the folded state, the image display device has a small difference in specular reflection hue between the images on both sides of the folded portion. can be obtained. |a ^* ₁ -a ^* ₂ | is preferably 0.50 or less, more preferably 0.30 or less, even more preferably 0.20 or less, and particularly preferably 0.10 or less. |b ^* ₁ -b ^* ₂ | is also preferably 0.50 or less, more preferably 0.30 or less, even more preferably 0.20 or less, and particularly preferably 0.10 or less. . |a ^* ₁ -a ^* ₂ | and |b ^* ₁ -b ^* ₂ | are preferably as small as possible, and are most preferably zero.

The first retardation layer 14 and the second retardation layer 24 may each be a single layer as shown in FIG. and may have a laminated structure. Each configuration will be described below. 1 and FIGS. 4(a) to 4(c) show the configuration in which the first retardation layer 14 and the second retardation layer 24 are single layers.

When the first retardation layer 14 and the second retardation layer 24 are single layers, each of the first retardation layer 14 and the second retardation layer 24 can typically function as a λ/4 plate. Specifically, Re(550) of each retardation layer is preferably 100 nm to 180 nm. In this case, the angle between the slow axis of the first retardation layer 14 and the absorption axis of the first polarizer 12 is preferably 40° to 50°, and the slow axis of the second retardation layer 24 The angle formed with the absorption axis of the second polarizer 22 is preferably 40° to 50°. In this embodiment, the first image display unit 10 includes a retardation layer (not shown) exhibiting refractive index characteristics of nz>nx=ny between the first retardation layer 14 and the first display cell 16. have more. Similarly, the second image display section 20 further has a retardation layer (not shown) exhibiting refractive index characteristics of nz>nx=ny between the second retardation layer 24 and the second display cell 26 . In this specification, a retardation layer exhibiting refractive index characteristics of nz>nx=ny may be referred to as another retardation layer.

When the first retardation layer 14 and the second retardation layer 24 have a laminated structure, the first retardation layer 14 typically has an H layer 14H and a Q layer 14Q, and the second retardation layer 24 is It typically has an H layer 24H and a Q layer 24Q. Each H layer 14H and 24H can typically function as a λ/2 plate, and each Q layer 14Q and 24Q can typically function as a λ/4 plate. Specifically, Re(550) of each H layer is preferably between 200 nm and 300 nm, and Re(550) of each Q layer is preferably between 100 nm and 180 nm. In this case, the angle between the slow axis of the H layer 14H of the first retardation layer and the absorption axis of the first polarizer 12 is preferably 10° to 20°, and the angle of the Q layer 14Q of the first retardation layer The angle between the slow axis and the absorption axis of the first polarizer 12 is preferably 70° to 80°. Similarly, the angle between the slow axis of the H layer 24H of the second retardation layer and the absorption axis of the second polarizer 22 is preferably 10° to 20°, and the angle of the Q layer 24Q of the second retardation layer The angle between the slow axis and the absorption axis of the second polarizer 22 is preferably 70° to 80°. The arrangement order of the H layer and the Q layer may be reversed, and the angle formed by the slow axis of the H layer and the absorption axis of the polarizer and the angle formed by the slow axis of the Q layer and the absorption axis of the polarizer The angles may be reversed.

The first polarizer 12 and the second polarizer 22 may be the same or may differ in detailed configuration. Similarly, the first retardation layer 14 and the second retardation layer 24 may be the same or different in detailed configuration. A protective layer (not shown) may be provided on one side or both sides of each of the first polarizer 12 and the second polarizer 22 .

The present invention can be applied to any suitable foldable image display device. Representative examples of image display devices include organic electroluminescence (EL) display devices, liquid crystal display devices, and quantum dot display devices. Preferably, it is an organic EL display device. The effect of the present invention is remarkable in the organic EL display device. Regarding the configuration of the image display device, a configuration well known in the industry may be employed for items not described in this specification.

Hereinafter, the polarizer, the protective layer (if present) and the retardation layer, which are constituent elements of the image display device, will be specifically described. Unless otherwise specified, each layer and optical film constituting the image display device are laminated via any appropriate adhesive layer (eg, adhesive layer, adhesive layer). In the following description, the first polarizer 12 and the second polarizer 22 are collectively referred to as a polarizer, and the first retardation layer 14 and the second retardation layer 24 are collectively referred to as a retardation layer. explain.

B. Polarizer Any appropriate polarizer can be employed as the polarizer. For example, the resin film forming the polarizer may be a single-layer resin film or a laminate of two or more layers.

Specific examples of the polarizer composed of a single-layer resin film include hydrophilic polymer films such as polyvinyl alcohol (PVA) films, partially formalized PVA films, and partially saponified ethylene/vinyl acetate copolymer films. In addition, polyene-based oriented films such as those subjected to dyeing treatment and stretching treatment with dichroic substances such as iodine and dichroic dyes, and dehydrated PVA and dehydrochlorinated polyvinyl chloride films. A polarizer obtained by dyeing a PVA-based film with iodine and uniaxially stretching the film is preferably used because of its excellent optical properties.

The dyeing with iodine is performed by, for example, immersing the PVA-based film in an aqueous iodine solution. The draw ratio of the uniaxial drawing is preferably 3 to 7 times. Stretching may be performed after the dyeing treatment, or may be performed while dyeing. Moreover, you may dye after extending|stretching. If necessary, the PVA-based film is subjected to swelling treatment, cross-linking treatment, washing treatment, drying treatment, and the like. For example, by immersing the PVA-based film in water and washing it with water before dyeing, not only can dirt and anti-blocking agents on the surface of the PVA-based film be washed away, but also the PVA-based film can be swollen to remove uneven dyeing. can be prevented.

Specific examples of the polarizer obtained using a laminate include a laminate of a resin substrate and a PVA-based resin layer (PVA-based resin film) laminated on the resin substrate, or a resin substrate and the resin A polarizer obtained by using a laminate with a PVA-based resin layer formed by coating on a substrate can be mentioned. A polarizer obtained by using a laminate of a resin base material and a PVA-based resin layer formed by coating on the resin base material is obtained, for example, by applying a PVA-based resin solution to the resin base material and drying the resin base material. forming a PVA-based resin layer thereon to obtain a laminate of a resin substrate and a PVA-based resin layer; stretching and dyeing the laminate to use the PVA-based resin layer as a polarizer; obtain. In this embodiment, stretching typically includes immersing the laminate in an aqueous boric acid solution and stretching. Furthermore, stretching may further include stretching the laminate in air at a high temperature (eg, 95° C. or higher) before stretching in an aqueous boric acid solution, if necessary. The obtained resin substrate/polarizer laminate may be used as it is (that is, the resin substrate may be used as a protective layer for the polarizer), or the resin substrate may be peeled off from the resin substrate/polarizer laminate. Then, any appropriate protective layer may be laminated on the release surface according to the purpose. Details of a method for manufacturing such a polarizer are described, for example, in Japanese Patent Application Laid-Open No. 2012-73580. The publication is incorporated herein by reference in its entirety.

式（１）において、Ｑ^１は、置換または非置換のアリール基を表し、Ｑ^２は、置換または非置換のアリーレン基を表し、Ｒ^１は、それぞれ独立して、水素原子、置換または非置換のアルキル基、置換または非置換のアセチル基、置換または非置換のベンゾイル基、置換または非置換のフェニル基を表し、Ｍは対イオンを表し、ｍは０～２の整数であり、ｎは０～６の整数であり；ただし、ｍおよびｎの少なくとも一方は０でなく、１≦ｍ＋ｎ≦６であり、ｍが２である場合、それぞれのＲ^１は同一であってもよく異なっていてもよい。 Another example of a polarizer obtained using a laminate is a polarizer configured as an aligned layer of a liquid crystal compound (hereinafter sometimes referred to as a liquid crystalline polarizer). The liquid crystalline polarizer includes, for example, a liquid crystalline polarizer obtained by applying a liquid crystalline coating liquid to a resin base material and drying the liquid crystalline coating liquid. The liquid crystalline polarizer contains, for example, an aromatic disazo compound represented by the following formula (1):

In formula (1), Q ¹ represents a substituted or unsubstituted aryl group, Q ² represents a substituted or unsubstituted arylene group, and each R ¹ independently represents a hydrogen atom, substituted or unsubstituted an alkyl group, a substituted or unsubstituted acetyl group, a substituted or unsubstituted benzoyl group, a substituted or unsubstituted phenyl group, M represents a counterion, m is an integer of 0 to 2, n is 0 is an integer of ~6; provided that at least one of m and n is not 0 and 1 ≤ m + n ≤ 6, and when m is 2, each R ¹ may be the same or different good.

A liquid crystalline polarizer can be produced, for example, by a method including the following steps B and C. Process A may be performed before process B, and process D may be performed after process C, as needed.
Step A: A step of subjecting the surface of the substrate to orientation treatment.
Step B: A step of applying a coating liquid containing the aromatic disazo compound represented by the above formula (1) to the surface of the substrate to form a coating film.
Step C: A step of drying the coating film to form a polarizer that is a dry coating film.
Step D: A step of subjecting the surface of the polarizer obtained in Step C to water resistance treatment.

Another example of a liquid crystalline polarizer is obtained by coating a substrate with a composition containing a polymerizable liquid crystal compound, a polymerizable non-liquid crystal compound, a dichroic dye, a polymerization initiator and a solvent, followed by copolymerization. and polarizers. In this specification, the term "aligned and fixed layer of a liquid crystal compound" also includes a layer (hardened layer) obtained by (co)polymerization of such a polymerizable liquid crystal compound.

Details of constituent materials and manufacturing methods of liquid crystalline polarizers are described in, for example, JP-A-2009-173849, JP-A-2018-151603, and JP-A-2018-84845. The descriptions of these publications are incorporated herein by reference.

The thickness of the polarizer (iodine-based polarizer) is preferably 25 μm or less, more preferably 1 μm to 12 μm, even more preferably 3 μm to 12 μm, particularly preferably 3 μm to 8 μm. If the thickness of the polarizer is within such a range, it is possible to satisfactorily suppress curling during heating, and obtain excellent durability in appearance during heating. The thickness of the liquid crystalline polarizer is preferably 1000 nm or less, more preferably 700 nm or less, and particularly preferably 500 nm or less. The lower limit of the thickness of the liquid crystalline polarizer is preferably 100 nm, more preferably 200 nm, and particularly preferably 300 nm.

The polarizer preferably exhibits absorption dichroism at any wavelength of 380 nm to 780 nm. The single transmittance of the polarizer is preferably 42.0% to 46.0%, more preferably 44.5% to 46.0%. The degree of polarization of the polarizer is preferably 97.0% or higher, more preferably 99.0% or higher, still more preferably 99.9% or higher.

C. Protective Layer The protective layer is formed of any suitable film that can be used as a protective layer for a polarizer. Specific examples of materials that are the main component of the film include cellulose resins such as triacetyl cellulose (TAC), polyesters, polyvinyl alcohols, polycarbonates, polyamides, polyimides, polyethersulfones, and polysulfones. , polystyrene-based, polynorbornene-based, polyolefin-based, (meth)acrylic-based, and acetate-based transparent resins. Thermosetting resins such as (meth)acrylic, urethane, (meth)acrylic urethane, epoxy, and silicone, or ultraviolet curable resins may also be used. In addition, for example, a glassy polymer such as a siloxane-based polymer can also be used. Further, polymer films described in JP-A-2001-343529 (WO01/37007) can also be used. Materials for this film include, for example, a resin composition containing a thermoplastic resin having a substituted or unsubstituted imide group in a side chain and a thermoplastic resin having a substituted or unsubstituted phenyl group and nitrile group in a side chain. can be used, for example, a resin composition comprising an alternating copolymer of isobutene and N-methylmaleimide and an acrylonitrile/styrene copolymer. The polymer film can be, for example, an extrudate of the resin composition.

When a protective layer is provided on the viewing side of the polarizer (the side opposite to the retardation layer), the protective layer may be subjected to surface treatment such as hard coat treatment, antireflection treatment, anti-sticking treatment, and anti-glare treatment, if necessary. may be applied.

When a protective layer is provided between the polarizer and the retardation layer, the protective layer is preferably optically isotropic. As used herein, “optically isotropic” means that the in-plane retardation Re (550) is 0 nm to 10 nm and the thickness direction retardation Rth (550) is −10 nm to +10 nm. say.

Any appropriate thickness can be adopted as the thickness of the protective layer. The thickness of the protective layer is, for example, 15 μm to 45 μm, preferably 20 μm to 40 μm. In addition, when the surface treatment is performed, the thickness of the protective layer is the thickness including the thickness of the surface treatment layer.

D. Retardation layer D-1. Single Layer Retardation Layer When the retardation layer is a single layer, it can typically function as a λ/4 plate, as described above. A retardation layer is typically provided to impart antireflection properties to an image display device. The retardation layer typically exhibits a refractive index characteristic of nx>ny=nz. The in-plane retardation Re(550) of the retardation layer is preferably 100 nm to 180 nm, more preferably 110 nm to 170 nm, still more preferably 120 nm to 160 nm. Here, "ny=nz" includes not only the case where ny and nz are completely equal but also the case where they are substantially equal. Therefore, ny>nz or ny<nz may be satisfied within a range that does not impair the effects of the present invention.

The Nz coefficient of the retardation layer is preferably 0.9 to 1.5, more preferably 0.9 to 1.3. By satisfying such a relationship, it is possible to obtain an image display device having a very excellent reflective hue.

The retardation layer may exhibit a reverse wavelength dispersion characteristic in which the retardation value increases according to the wavelength of the measurement light, or may exhibit a positive wavelength dispersion characteristic in which the retardation value decreases according to the wavelength of the measurement light. It may well exhibit a flat wavelength dispersion characteristic in which the retardation value hardly changes even with the wavelength of the measurement light. In one embodiment, the retardation layer exhibits reverse wavelength dispersion characteristics. In this case, Re(450)/Re(550) of the retardation layer is preferably 0.8 or more and less than 1, more preferably 0.8 or more and 0.95 or less. With such a configuration, very excellent antireflection properties can be achieved.

The angle formed by the slow axis of the retardation layer and the absorption axis of the polarizer is preferably 40° to 50°, more preferably 42° to 48°, and still more preferably about 45° as described above. be. If the angle is within such a range, an image display device having extremely excellent antireflection properties can be obtained by using a λ/4 plate as the retardation layer as described above.

The retardation layer may be made of any appropriate material as long as the properties as described above can be satisfied. Specifically, the retardation layer may be a stretched resin film or an oriented and solidified layer of a liquid crystal compound. A retardation layer composed of a stretched resin film is described in, for example, JP-A-2017-54093 and JP-A-2018-60014. Specific examples of the liquid crystal compound and details of the method for forming the alignment fixed layer are described, for example, in JP-A-2006-163343. The descriptions of these publications are incorporated herein by reference.

The thickness of the retardation layer can typically be set to a thickness that allows it to function properly as a λ/4 plate. When the retardation layer is a stretched resin film, the thickness of the retardation layer may be, for example, 10 μm to 50 μm. When the retardation layer is a fixed alignment layer of a liquid crystal compound, the thickness of the retardation layer may be, for example, 1 μm to 5 μm.

D-2. Retardation layer having a laminated structure When the retardation layer has a laminated structure (substantially, a two-layer structure), typically one functions as a λ / 4 plate and the other functions as a λ / 2 plate. can. In the illustrated example above, the H layer functions as a λ/2 plate and the Q layer functions as a λ/4 plate. Therefore, the thicknesses of the H and Q layers can be adjusted to obtain the desired in-plane retardation of the λ/2 plate or λ/4 plate. When the H layer is a stretched film of a resin film, the thickness of the H layer can be, for example, 20 μm to 70 μm. When the H layer is a fixed alignment layer of a liquid crystal compound, the thickness of the retardation layer may be, for example, 2 μm to 7 μm. In this case, the in-plane retardation Re(550) of the H layer is preferably 200 nm to 300 nm, more preferably 230 nm to 290 nm, still more preferably 250 nm to 280 nm. The thickness and in-plane retardation Re(550) of the Q layer are as described in section D-1 above for the single layer. The angle formed by the slow axis of the H layer and the absorption axis of the polarizer is preferably 10° to 20°, more preferably 12° to 18°, and still more preferably about 15° as described above. . The angle formed by the slow axis of the Q layer and the absorption axis of the polarizer is preferably 70° to 80°, more preferably 72° to 78°, and still more preferably about 75° as described above. . With such a configuration, it is possible to obtain characteristics close to ideal reverse wavelength dispersion characteristics, and as a result, very excellent antireflection characteristics can be realized. Materials constituting the H layer and the Q layer, formation methods, optical characteristics, etc. are as described in the above section D-1 regarding the single layer.

E. Alternative Retardation Layer As described above, the alternative retardation layer can be a so-called positive C plate whose refractive index characteristics exhibit a relationship of nz>nx=ny. By using a positive C plate as another retardation layer, it is possible to satisfactorily prevent reflection in oblique directions and widen the viewing angle of the antireflection function. Another retardation layer is provided, as described above, typically when the retardation layer is a single layer. The thickness direction retardation Rth (550) of the different retardation layer is preferably −50 nm to −300 nm, more preferably −70 nm to −250 nm, still more preferably −90 nm to −200 nm, particularly preferably −100 nm to −. 180 nm. Here, "nx=ny" includes not only the case where nx and ny are strictly equal but also the case where nx and ny are substantially equal. That is, the in-plane retardation Re(550) of another retardation layer can be less than 10 nm.

Another retardation layer may be formed of any appropriate material. Another retardation layer preferably consists of a film containing a liquid crystal material fixed in homeotropic alignment. A liquid crystal material (liquid crystal compound) that can be homeotropically aligned may be a liquid crystal monomer or a liquid crystal polymer. Specific examples of the liquid crystal compound and the method for forming the retardation layer include the liquid crystal compound and the method for forming the retardation layer described in [0020] to [0028] of JP-A-2002-333642. In this case, the thickness of the separate retardation layer is preferably 0.5 μm to 10 μm, more preferably 0.5 μm to 8 μm, still more preferably 0.5 μm to 5 μm.

F. Circularly polarizing plate The polarizer, the protective layer (if present), the retardation layer and another retardation layer (if present) according to items B to E above are provided as an integral circular polarizing plate, and the display cell It can be laminated. Accordingly, embodiments of the present invention also include such circular polarizers. The circularly polarizing plate may be a single film (laminated film) in which a first portion corresponding to the first image display portion and a second portion corresponding to the second image display portion are integrated. It may be provided as a set of the first circularly polarizing plate laminated on the display cell of the image display section and the second circularly polarizing plate laminated on the display cell of the second image display section. The details of each layer constituting the circularly polarizing plate are as described in the above sections A to E regarding the image display device. A case where the circularly polarizing plate is a single film will be briefly described below.

In the circularly polarizing plate provided as a single film, a first portion corresponding to the first image display portion and a second portion corresponding to the second image display portion are integrated, and the first portion and the second portion are integrated. A fold center is defined as the boundary between the two parts. The boundary between the first part and the second part is preferably seamless. The first part has a first polarizer and a first retardation layer with circular polarization function or elliptical polarization function; the second part has a second polarizer and a second retardation layer with circular polarization function or elliptical polarization function a retardation layer; the first polarizer and the second polarizer are arranged such that their absorption axes are in a line-symmetrical relationship with respect to the bending center; and the first retardation layer and the second polarizer The retardation layers are arranged such that their respective slow axes are line-symmetrical with respect to the bending center. In such a circularly polarizing plate, each of the first retardation layer and the second retardation layer is preferably an alignment fixed layer of a liquid crystal compound. With such a configuration, the boundary between the first portion and the second portion can be made seamless.

A circularly polarizing plate provided as a single film can be produced, for example, by the following method: (a) the center of the width direction of any suitable elongated substrate as a boundary; defining the portions; (b) subjecting each of the first portion and the second portion to an orientation treatment; When the retardation layer is a single layer, the orientation treatment direction is 45° with respect to the longitudinal direction, and the orientation direction of the first portion and the orientation direction of the second portion are with respect to the boundary. (c) applying a liquid crystal compound to the alignment treatment surface and solidifying or curing the liquid crystal compound in an aligned state to form an alignment fixed layer; (d) forming an alignment fixed layer, The structure of the polarizer/retardation layer (aligned solidified layer of liquid crystal compound: alignment direction 45°) is transferred to a long polarizer having an absorption axis in the long direction, typically by roll-to-roll. A circularly polarizing plate having When the retardation layer has an H layer and a Q layer, an orientation fixed layer with an orientation angle of 15 ° with respect to the longitudinal direction and an orientation fixed with an orientation angle of 75 ° with respect to the longitudinal direction The layers may be sequentially transferred to the polarizer. In this way, a circularly polarizing plate having a structure of polarizer/H layer (fixed alignment layer of liquid crystal compound: alignment direction 15°)/Q layer (fixed alignment layer of liquid crystal compound: alignment direction 75°) can be obtained. .

EXAMPLES The present invention will be specifically described below with reference to Examples, but the present invention is not limited to these Examples. In addition, the measuring method of each characteristic is as follows.

(1) Thickness The thickness of the resin film was measured using a digital micrometer (KC-351C manufactured by Anritsu Co.), and the other thickness was measured using an interference film thickness meter (manufactured by Otsuka Electronics Co., Ltd., product name "MCPD-3000"). was measured using
(2) Retardation Value of Retardation Layer A sample of 50 mm×50 mm was cut out from the retardation layer used in Examples and Comparative Examples and used as a measurement sample. The in-plane phase difference of the prepared measurement sample was measured using a phase difference measuring device (product name: “KOBRA-WPR”) manufactured by Oji Scientific Instruments Co., Ltd. The in-plane retardation was measured at a wavelength of 590 nm and at a temperature of 23°C.
(3) a ^* value and b ^* value A black image was displayed on the image display device obtained in Examples and Comparative Examples, and a multi-angle variable automatic measurement spectrophotometer (manufactured by Gilent Technologies, product name “Cary 7000”) was used. UMS”).

[Production Example 1: Production of polarizer]
An A-PET (amorphous-polyethylene terephthalate) film (Mitsubishi Plastics Co., Ltd., trade name: NOVACLEAR SH046, thickness: 200 μm) was prepared as a substrate, and the surface was subjected to corona treatment (58 W/m ² /min). On the other hand, 1 wt% of acetoacetyl-modified PVA (manufactured by Nippon Synthetic Chemical Industry Co., Ltd., trade name: GOSEFIMER Z200, degree of polymerization: 1200, degree of saponification: 99.0% or more, degree of acetoacetyl modification: 4.6%) was added. Prepared PVA (degree of polymerization 4200, degree of saponification 99.2%) is prepared, coated so that the film thickness after drying is 12 μm, and dried by hot air drying in an atmosphere of 60 ° C. for 10 minutes. A laminate was prepared by providing a PVA-based resin layer on the material. Next, this laminate was first stretched 2.0 times at 130° C. in the air to obtain a stretched laminate. Next, the stretched laminate was immersed in a boric acid insolubilizing aqueous solution at a liquid temperature of 30° C. for 30 seconds to insolubilize the PVA-based resin layer in which the PVA molecules contained in the stretched laminate were oriented. The boric acid insolubilizing aqueous solution in this step had a boric acid content of 3% by weight with respect to 100% by weight of water. A colored laminate was produced by dyeing this stretched laminate. The colored laminate is obtained by immersing the stretched laminate in a dyeing solution containing iodine and potassium iodide at a liquid temperature of 30° C. to adsorb iodine to the PVA-based resin layer contained in the stretched laminate. The iodine concentration and the immersion time were adjusted so that the obtained polarizer had a single transmittance of 44.0%. Specifically, the dyeing solution uses water as a solvent, has an iodine concentration in the range of 0.08 to 0.25% by weight, and has a potassium iodide concentration in the range of 0.56 to 1.75% by weight. . The concentration ratio of iodine to potassium iodide was 1:7. Next, the colored laminate was immersed in a boric acid cross-linking aqueous solution at 30° C. for 60 seconds to cross-link the PVA molecules of the PVA-based resin layer to which iodine had been adsorbed. The boric acid cross-linking aqueous solution in this step had a boric acid content of 3% by weight with respect to 100% by weight of water, and a potassium iodide content of 3% by weight with respect to 100% by weight of water. Further, the obtained colored laminate was stretched in an aqueous boric acid solution at a stretching temperature of 70° C. in the same direction as the stretching in the air by a factor of 2.7 to obtain a final stretching ratio of 5.4. A laminate of substrate/polarizer (thickness: 5 μm) was obtained by doubling. The boric acid cross-linking aqueous solution in this step had a boric acid content of 6.5% by weight with respect to 100% by weight of water and a potassium iodide content of 5% by weight with respect to 100% by weight of water. The obtained laminate was taken out from the boric acid aqueous solution, and the boric acid adhering to the surface of the polarizer was washed with an aqueous solution containing 2% by weight of potassium iodide with respect to 100% by weight of water. The washed laminate was dried with hot air at 60°C.

[Production Example 2: Production of Retardation Film Constituting Retardation Layer]
1-1. Preparation of polycarbonate resin film Isosorbide (ISB) 26.2 parts by mass, 9,9-[4-(2-hydroxyethoxy)phenyl]fluorene (BHEPF) 100.5 parts by mass, 1,4-cyclohexanedimethanol (1, 4-CHDM) 10.7 parts by mass, diphenyl carbonate (DPC) 105.1 parts by mass, and cesium carbonate (0.2% by mass aqueous solution) 0.591 parts by mass as a catalyst were charged into a reaction vessel, and a nitrogen atmosphere was added. Below, as the first step of the reaction, the temperature of the heat medium in the reaction vessel was set to 150° C., and the raw materials were dissolved with stirring as necessary (about 15 minutes).
Next, the pressure inside the reaction vessel was changed from normal pressure to 13.3 kPa, and the generated phenol was discharged out of the reaction vessel while raising the temperature of the heat medium in the reaction vessel to 190° C. over 1 hour.
After maintaining the temperature in the reaction vessel at 190° C. for 15 minutes, the pressure in the reaction vessel is increased to 6.67 kPa and the temperature of the heating medium in the reaction vessel is raised to 230° C. in 15 minutes as the second step, The generated phenol was drawn out of the reaction vessel. Since the stirring torque of the stirrer increased, the temperature was raised to 250° C. in 8 minutes, and the pressure in the reaction vessel was reduced to 0.200 kPa or less in order to remove the generated phenol. After reaching a predetermined stirring torque, the reaction was terminated, and the produced reaction product was extruded into water and then pelletized to obtain BHEPF/ISB/1,4-CHDM=47.4 mol%/37.1 mol%. /15.5 mol % of polycarbonate resin was obtained.
The obtained polycarbonate resin had a glass transition temperature of 136.6° C. and a reduced viscosity of 0.395 dL/g.
After vacuum drying the obtained polycarbonate resin at 80 ° C. for 5 hours, a single screw extruder (manufactured by Isuzu Kakoki Co., Ltd., screw diameter 25 mm, cylinder set temperature: 220 ° C.), T die (width 200 mm, set temperature: 220 ° C.), a chill roll (set temperature: 120 to 130° C.) and a film forming apparatus equipped with a winder to prepare a polycarbonate resin film having a thickness of 120 μm.

1-2. Production of Retardation Film Using a tenter stretching machine, the obtained polycarbonate resin film was laterally stretched to obtain a retardation film having a thickness of 50 μm. At that time, the draw ratio was 250% and the drawing temperature was 137 to 139°C.
Re(590) of the obtained retardation film was 147 nm, and Re(450)/Re(550) was 0.89. Furthermore, the retardation film exhibited refractive index characteristics of nx>ny=nz.

[Production Example 3: Production of another retardation layer]
20 parts by weight of a side-chain type liquid crystal polymer represented by the following chemical formula (I) (numbers 65 and 35 in the formula indicate mol % of monomer units, and are expressed as block polymer for convenience: weight average molecular weight 5000); 80 parts by weight of a polymerizable liquid crystal exhibiting a nematic liquid crystal phase (manufactured by BASF: trade name Paliocolor LC242) and 5 parts by weight of a photopolymerization initiator (manufactured by Ciba Specialty Chemicals: trade name Irgacure 907) are dissolved in 200 parts by weight of cyclopentanone. Then, a liquid crystal coating liquid was prepared. Then, after coating the coating solution on a substrate film (norbornene resin film: Nippon Zeon Co., Ltd., trade name “Zeonex”) with a bar coater, the liquid crystal is formed by heating and drying at 80 ° C. for 4 minutes. Oriented. By irradiating this liquid crystal layer with ultraviolet rays and curing the liquid crystal layer, an alignment solidified layer of a liquid crystal compound (liquid crystal alignment solidified layer, thickness 0.58 μm) was formed as another retardation layer on the substrate. This layer had an Re(590) of 0 nm and an Rth(590) of −100 nm, showing refractive index characteristics of nz>nx=ny.

[Production Example 4: Preparation of liquid crystal compound aligned and fixed layer (liquid crystal aligned and fixed layer) constituting retardation layer]
55 parts of the compound represented by formula (II), 25 parts of the compound represented by formula (III), and 20 parts of the compound represented by formula (IV) were added to 400 parts of cyclopentanone (CPN), and then 60 After heating to ° C., stirring and dissolving, and confirming dissolution, returning to room temperature, 3 parts of Irgacure 907 (manufactured by BASF Japan Co., Ltd.), Megafac F-554 (manufactured by DIC Corporation) 0.2 parts, 0.1 part of p-methoxyphenol (MEHQ) was added and further stirred to obtain a solution. The solution was clear and homogeneous. The resulting solution was filtered through a 0.20 μm membrane filter to obtain a polymerizable composition. On the other hand, a polyimide solution for an alignment film was applied to a glass substrate having a thickness of 0.7 mm by spin coating, dried at 100° C. for 10 minutes, and then baked at 200° C. for 60 minutes to obtain a coating film. . The resulting coating film was rubbed to form an alignment film. The rubbing treatment was performed using a commercially available rubbing device. The polymerizable composition obtained above was applied to a substrate (substantially an alignment film) by a spin coating method and dried at 100° C. for 2 minutes. After cooling the obtained coating film to room temperature, it was irradiated with ultraviolet rays for 30 seconds at an intensity of 30 mW/cm ² using a high-pressure mercury lamp to obtain a liquid crystal alignment fixed layer. The in-plane retardation Re(550) of the liquid crystal alignment fixed layer was 130 nm. In addition, the Re(450)/Re(550) of the liquid crystal alignment fixed layer was 0.851, showing reverse dispersion wavelength characteristics.

ポリエチレンテレフタレート（ＰＥＴ）フィルム（厚み３８μｍ）表面を、ラビング布を用いてラビングし、所定の方向に配向処理を施した。この配向処理表面に、上記液晶塗工液をバーコーターにより塗工し、９０℃で２分間加熱乾燥することによって液晶化合物を配向させた。このようにして形成された液晶層に、メタルハライドランプを用いて１ｍＪ/ｃｍ^２の光を照射し、当該液晶層を硬化させることによって、ＰＥＴフィルム上に液晶配向固化層を形成した。液晶配向固化層の厚みは２．５μｍ、面内位相差Ｒｅ（５９０）は２６０ｎｍであった。液晶配向固化層は、正の波長分散特性を示した。さらに、液晶配向固化層は、ｎｘ＞ｎｙ＝ｎｚの屈折率特性を示した。 [Production Example 5: Production of Liquid Crystal Alignment Fixed Layer Constituting Layer H]
Polymerizable liquid crystal exhibiting a nematic liquid crystal phase (manufactured by BASF: trade name “Paliocolor LC242”, represented by the following formula) 10 g, and a photopolymerization initiator for the polymerizable liquid crystal compound (manufactured by BASF: trade name “Irgacure 907 ”) was dissolved in 40 g of toluene to prepare a liquid crystal composition (coating liquid).

The surface of a polyethylene terephthalate (PET) film (thickness: 38 μm) was rubbed with a rubbing cloth and subjected to orientation treatment in a predetermined direction. The above liquid crystal coating solution was applied to the alignment-treated surface using a bar coater, and dried by heating at 90° C. for 2 minutes to align the liquid crystal compound. The thus formed liquid crystal layer was irradiated with light of 1 mJ/cm ² using a metal halide lamp to cure the liquid crystal layer, thereby forming a liquid crystal alignment fixed layer on the PET film. The liquid crystal alignment fixed layer had a thickness of 2.5 μm and an in-plane retardation Re (590) of 260 nm. The liquid crystal alignment fixed layer exhibited a positive wavelength dispersion characteristic. Furthermore, the liquid crystal alignment fixed layer exhibited refractive index characteristics of nx>ny=nz.

[Production Example 6: Production of Liquid Crystal Alignment Fixed Layer Constituting Q Layer]
A liquid crystal alignment fixed layer was formed on a PET film in the same manner as in Production Example 5 except that the coating thickness was changed. The liquid crystal alignment fixed layer had a thickness of 1.5 μm and an in-plane retardation Re (590) of 120 nm.

[Example 1]
1-1. Preparation of retardation layer-attached polarizing plate On the polarizer surface of the substrate/polarizer laminate obtained in Production Example 1, the retardation film (retardation layer ) were pasted together. Here, they were attached so that the angle between the absorption axis of the polarizer and the slow axis of the retardation layer (retardation film) was +45°. Furthermore, the A-PET film of the substrate is peeled off from the laminate, and an acrylic film having a thickness of 40 μm is attached to the peeled surface via a PVA adhesive to form a protective layer/polarizer/retardation layer. A laminate having Then, the liquid crystal alignment solidified layer (another retardation layer) obtained in Production Example 3 is transferred to the surface of the retardation layer, and a circle having a configuration of protective layer / polarizer / retardation layer / another retardation layer A polarizing plate was obtained. Furthermore, in the same manner as above except that the angle between the absorption axis of the polarizer and the slow axis of the retardation layer (retardation film) is -45 °, protective layer / polarizer / retardation layer / A circularly polarizing plate having another retardation layer structure was obtained.

1-2. Preparation of organic EL display device An organic EL panel was removed from an organic EL display device (manufactured by Samsung, product name “Galaxy S5”), and the polarizing film attached to the organic EL panel was peeled off to form an organic EL cell. . Two organic EL cells were prepared for the left screen and the right screen. The circularly polarizing plate obtained above was attached to each of the two organic EL cells to produce two organic EL display devices. The two organic EL display devices are the left screen (first image display unit) and the right screen (second image display unit), respectively, and the axis angles of the polarizers and the retardation layers are shown in FIG. The left screen and the right screen were arranged so as to form the organic EL display device of this example. The organic EL display device was subjected to the evaluation of (3) above in a state corresponding to the state in which the left screen and the right screen were folded. More specifically, for the left screen, the a ^* value and b ^* value were measured at an azimuth angle of 120° and a polar angle of 30°, and for the right screen, the a ^* value was measured at an azimuth angle of 60° and a polar angle of -30°. and b ^* values were measured. Table 1 shows the results. The angles of the axial directions in the table are 0° in the vertical direction and 90° in the horizontal direction, with the vertical direction (0°) as a reference, plus counterclockwise rotation (not shown) and minus clockwise rotation. Additionally, FIG.

[Examples 2 to 4]
An organic EL display device was produced in the same manner as in Example 1 except that the axis angles of the polarizers and retardation layers of the left and right screens were changed as shown in Table 1. The axial angle of Example 2 corresponds to FIG. 1, the axial angle of Example 3 corresponds to FIG. 4(c), and the axial angle of Example 4 corresponds to FIG. 4(a). The obtained organic EL display device was evaluated in the same manner as in Example 1. Table 1 shows the results.

[Example 5]
In the same manner as in Example 1 except that the liquid crystal alignment solidified layer obtained in Production Example 4 was used instead of the retardation film obtained in Production Example 2, protective layer / polarizer / retardation layer / separate were obtained. An organic EL display device was produced in the same manner as in Example 1 except that these circularly polarizing plates were used. The axial angle in this organic EL display device corresponds to FIG. 4(b). The obtained organic EL display device was evaluated in the same manner as in Example 1. Table 1 shows the results.

[Examples 6 to 8]
An organic EL display device was produced in the same manner as in Example 5, except that the axis angles of the polarizers and retardation layers of the left and right screens were changed as shown in Table 1. The axial angle of Example 6 corresponds to FIG. 1, the axial angle of Example 7 corresponds to FIG. 4(c), and the axial angle of Example 8 corresponds to FIG. 4(a). The obtained organic EL display device was evaluated in the same manner as in Example 1. Table 1 shows the results.

[Example 9]
Protective layer/polarizer/H layer/ Two circular polarizers with the configuration of Q layers were obtained. An organic EL display device was produced in the same manner as in Example 1 except that these circularly polarizing plates were used. The obtained organic EL display device was evaluated in the same manner as in Example 1. Table 1 shows the results.

[Examples 10-12]
An organic EL display device was produced in the same manner as in Example 9 except that the axis angles of the polarizers and retardation layers of the left and right screens were changed as shown in Table 1. The obtained organic EL display device was evaluated in the same manner as in Example 1. Table 1 shows the results.

[Comparative Examples 1 to 4]
An organic EL display device was produced in the same manner as in Example 1 except that the axis angles of the polarizers and retardation layers of the left and right screens were changed as shown in Table 1. That is, in the same manner as in Example 1, except that the absorption axis of the polarizer and the slow axis of the retardation layer of the left screen and the right screen are configured so as not to have a line-symmetrical positional relationship with respect to the bent portion. An organic EL display device was produced. The obtained organic EL display device was evaluated in the same manner as in Example 1. Table 1 shows the results. In addition, FIG. 6 shows the state of the reflection hues of the left screen and the right screen of the organic EL display device of Comparative Example 1 together with the results of Example 1. As shown in FIG.

[Comparative Examples 5 to 8]
An organic EL display device was produced in the same manner as in Example 5, except that the axis angles of the polarizers and retardation layers of the left and right screens were changed as shown in Table 1. That is, in the same manner as in Example 5, except that the absorption axis of the polarizer and the slow axis of the retardation layer of the left screen and the right screen are configured so as not to have a line-symmetrical positional relationship with respect to the bent portion. An organic EL display device was produced. The obtained organic EL display device was evaluated in the same manner as in Example 1. Table 1 shows the results.

[Comparative Examples 9 to 12]
An organic EL display device was produced in the same manner as in Example 9 except that the axis angles of the polarizers and retardation layers of the left and right screens were changed as shown in Table 1. That is, in the same manner as in Example 9, except that the absorption axis of the polarizer and the slow axis of the retardation layer of the left screen and the right screen are configured so as not to have a line-symmetrical positional relationship with respect to the bent portion. An organic EL display device was produced. The obtained organic EL display device was evaluated in the same manner as in Example 1. Table 1 shows the results.

<Evaluation>
As is clear from Table 1, according to the embodiments of the present invention, it is possible to obtain an image display device in which the difference in specular hue between the image on the left screen and the image on the right screen is small.

The image display device of the present invention is suitably used for televisions, displays, mobile phones, personal digital assistants, digital cameras, video cameras, portable game machines, car navigation systems, copiers, printers, facsimiles, clocks, microwave ovens and the like.

10 1st image display section 12 1st polarizer 14 1st retardation layer 14H H layer 14Q Q layer 16 1st display cell 20 2nd image display section 22 2nd polarizer 24 2nd retardation layer 24H H layer 24Q Q layer 26 second display cell 100 image display device 101 image display device

Claims (10)

a first image display portion; a second image display portion; and a bending center defined as a straight line of a connecting portion between one side of the first image display portion and one side of the second image display portion
The first image display portion and the second image display portion are configured to be foldable at the fold center,
The first image display unit has, in order from the viewing side, a first polarizer, a first retardation layer having a circularly polarized light function or an elliptically polarized light function, and a first display cell, and
The second image display unit has, in order from the viewing side, a second polarizer, a second retardation layer having a circularly polarized light function or an elliptically polarized light function, and a second display cell, and
The first polarizer and the second polarizer are arranged such that their absorption axes are in a line-symmetrical relationship with respect to the bending center, and the first retardation layer and the second retardation layer are , each slow axis is arranged so as to have a line-symmetrical relationship with respect to the bending center,
Image display device. Specular reflection hues (a ^* ₁ , b ^* ₁ ) in the 30° polar angle direction of the first image display unit and specular reflection hues (a ^* ₂ , b ^* ₂ ) in the 30° polar angle direction of the second image display unit ) satisfies the following relationship:
|a ^* ₁ -a ^* ₂ |<1.00
|b ^* ₁ −b ^* ₂ |<1.00 The first retardation layer and the second retardation layer are each a single layer, and Re (550) of each retardation layer is 100 nm to 180 nm,
The angle formed by the slow axis of the first retardation layer and the absorption axis of the first polarizer is 40 ° to 50 °, and the slow axis of the second retardation layer and the second polarizer The angle formed with the absorption axis of is 40 ° to 50 °,
3. The image display device according to claim 1 or 2. The first image display unit further has a retardation layer exhibiting a refractive index characteristic of nz>nx=ny between the first retardation layer and the first display cell,
The second image display unit further has a retardation layer exhibiting a refractive index characteristic of nz>nx=ny between the second retardation layer and the second display cell,
The image display device according to claim 3. The first retardation layer and the second retardation layer each have a laminated structure of an H layer and a Q layer, Re (550) of each H layer is 200 nm to 300 nm, and each Q layer Re (550) is 100 nm to 180 nm,
The angle formed by the slow axis of the H layer of the first retardation layer and the absorption axis of the first polarizer is 10 ° to 20 °, and the slow axis of the Q layer of the first retardation layer and the The angle formed with the absorption axis of the first polarizer is 70° to 80°,
The angle formed by the slow axis of the H layer of the second retardation layer and the absorption axis of the second polarizer is 10 ° to 20 °, and the slow axis of the Q layer of the second retardation layer and the The angle formed with the absorption axis of the second polarizer is 70° to 80°,
3. The image display device according to claim 1 or 2. 6. The method according to any one of claims 1 to 5, wherein said first image display section and said second image display section are integrated, and a bending center is defined as a boundary between said first image display section and said second image display section. The image display device according to any one of the above. 7. The image display device according to any one of claims 1 to 6, which is an organic electroluminescence display device. A circularly polarizing plate used in the image display device according to any one of claims 1 to 7,
A first portion corresponding to the first image display portion and a second portion corresponding to the second image display portion are integrated,
A bending center is defined as a boundary between the first portion and the second portion;
The first part has a first polarizer and a first retardation layer having a circularly polarized light function or an elliptically polarized light function,
The second part has a second polarizer and a second retardation layer having a circularly polarized light function or an elliptically polarized light function,
The first polarizer and the second polarizer are arranged such that their absorption axes are in a line-symmetrical relationship with respect to the bending center, and the first retardation layer and the second retardation layer are , each slow axis is arranged so as to have a line-symmetrical relationship with respect to the bending center,
circular polarizer. 9. The circularly polarizing plate according to claim 8, wherein each of said first retardation layer and said second retardation layer is an alignment fixed layer of a liquid crystal compound. 10. The circularly polarizing plate according to claim 8, wherein each of said first polarizer and said second polarizer is an alignment fixed layer of a liquid crystal compound.

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